Introduction to Convergence at the Nanoscale
- Jul 27, 2007
Nanoscience and nanotechnology are not merely "the next big things," offering investors the chance to get in on the ground floor of new industries. More importantly, they promote the unification of most branches of science and technology, based on the unity of nature at the nanoscale. Already, information technology incorporates hardware with nanoscale components, and biotechnology is merging with nanotechnology in many areas. Indeed, unless these technologies converge, further progress in most fields will be impossible. More controversially—but also more significantly—the convergence is prepared to encompass cognitive science. This vast unification is often called NBIC, from the initials of its four main components: Nanotechnology, Biotechnology, Information technology, and Cognitive science. The result will be new cognitive technologies that promise to put the behavioral and social sciences for the first time on a rigorous foundation.
This book reports the latest developments in, and tantalizing possibilities related to, convergence at the nanoscale. The perspective taken here is that of a social and information scientist who has been centrally involved in major collaborative projects to assess the implications of nanoscience and nanotechnology.
The Meaning of "Nano"
Convergence of NBIC technologies will be based on material unity at the nanoscale and on technology integration from that scale. The building blocks of matter that are fundamental to all sciences originate at the nanoscale—that is, the scale at which complex inorganic materials take on the characteristic mechanical, electrical, and chemical properties they exhibit at larger scales. The nanoscale is where the fundamental structures of life arise inside biological cells, including the DNA molecule itself. Soon, the elementary electronic components that are the basis of information technology will be constructed at the nanoscale. Understanding the function of the human brain requires research on nanoscale phenomena at receptor sites on neurons, and much brain research will be facilitated by nanoscale components in microsensor arrays and comparable scientific tools. Thus nanotechnology will play an essential role both in achieving progress in each of the four fields and in unifying them all.
Although perhaps everyone understands that "nano" concerns the very small, it is nevertheless difficult to get a picture of how small a nanometer really is: one billionth (thousand-millionth) of a meter. A billionth of a meter is the same as a millionth of a millimeter, and the smallest U.S. coin, the "thin" dime, is about a millimeter in thickness. If you were somehow able to shrink yourself down until you were only a nanometer tall, then in comparison a dime would seem to be 175 kilometers (about 100 miles) thick. The DNA in the cells of our bodies is between 2 and 3 nanometers thick, though as much as several millimeters long, so it has the proportions of a long piece of fine thread, curled up inside the chromosomes. Atoms and water molecules are smaller than a nanometer, whereas the wavelength of visible light ranges from approximately 400 nanometers at the violet end of the spectrum to approximately 700 nanometers at the red.
In 1960, the General Conference on Weights and Measures refined the metric system of measurement, among other things defining the nanometer as one billionth of a meter. Another unit for measuring tiny distances was already widely used in spectroscopy and nuclear physics, the ångström, which is 0.1 nanometer. In principle, the ångström became obsolete in 1960, but, in fact, it is still used today.
During the next few years, "nano" concepts became widely disseminated throughout the cultures of civilized nations. For example, the 1966–1967 sci-fi television series Time Tunnel used the word "nanosecond" as part of the countdown to operate its time machine: "One second, millisecond, microsecond, nanosecond!" The term "nanotechnology" was apparently first used by Professor Norio Taniguchi of Tokyo Science University in a 1974 paper, in which it described the ultimate standard for precision engineering."1
Recently, people have been coining "nanowords" at a furious pace. For an article I published in The Journal of Nanoparticle Research in 2004, I counted titles containing "nano" on the Amazon.com website, finding 180 books that fit the bill.2 Some contain two "nano" words, such as Societal Implications of Nanoscience and Nanotechnology, edited by Mihail ("Mike") C. Roco and myself in 2000. Altogether, there were 221 "nano" words in the titles of these 180 books. Nanotechnology is most common, appearing 94 times. Nanostructure (or a variant like nanostructured) appeared 28 times, and nano, 18 times. These words appeared five times: nanocomposite, nanofabrication, nanomaterials, nanophase, nanotribology, nanoscale, and nanoscience. Nanosystems appeared four times, and nanoengineering, nanoindentation, nanomeeting, and nanoparticles appeared three times each. Bionanotechnology appeared twice, as did nanocrystalline, nanoelectronics, nanometer, nanophotonics, nanotech, and nanoworld. Sixteen other words appeared once in the titles: nanobelts, nanobiology, nanocosm, nanodevices, nanoelectromechanics, nanolithography, nanomechanics, nanomedicine, nanometric, nanometrology, nanoporous, nanopositioning, nanoscopy, nanosources, nanotubes, and nanowires. Clearly, we are facing a nanocraze, nanofad, or nanohype.
This welter of words may bring pure nano into disrepute, because it seems to be claiming too much scope for the field. Nevertheless, it would be a mistake to think that nanotechnology is a specific technical approach, such as the fabled nanoscale robots that some visionaries imagine. Rather, the nanoscale is the region where many technologies meet, combine, and creatively generate a world of possibilities. The official website of the National Nanotechnology Initiative (NNI; www.nano.gov) defines the field as follows:
- Nanotechnology is the understanding and control of matter at dimensions of roughly 1 to 100 nanometers, where unique phenomena enable novel applications. Encompassing nanoscale science, engineering, and technology, nanotechnology involves imaging, measuring, modeling, and manipulating matter at this length scale. At the nanoscale, the physical, chemical, and biological properties of materials differ in fundamental and valuable ways from the properties of individual atoms and molecules or bulk matter. Nanotechnology R&D is directed toward understanding and creating improved materials, devices, and systems that exploit these new properties.
For NNI leader Mike Roco (Figure 1-1), the scientific challenges of this length scale are as immense as the technical opportunities:
- We know most about single atoms and molecules at one end, and on bulk behavior of materials and systems at the other end. We know less about the intermediate length scale—the nanoscale, which is the natural threshold where all living systems and man-made systems work. This is the scale where the first level of organization of molecules and atoms in nanocrystals, nanotubes, nanobiomotors, etc., is established. Here, the basic properties and functions of material structures and systems are defined, and even more importantly can be changed as a function of organization of matter via "weak" molecular interactions.3
Figure 1-1 Mihail C. Roco, Senior Advisor for Nanotechnology to the Directorate for Engineering, National Science Foundation. Mike has not only been the most forceful advocate for nanoscience and technology, but also originated many of the key ideas in NBIC convergence on the basis of considering the societal implications of nanotechnology.
When I first became professionally involved with nanotechnology, I was a member of the scientific staff of the Directorate for Social, Behavioral, and Economic Sciences of the National Science Foundation (NSF). Since 1993, I had been representing the directorate on computer-oriented cross-cutting initiatives, such as High-Performance Computing and Communications, the Digital Library Initiative, and Information Technology Research. I was a lifelong technology enthusiast, having written three books about the space program, experimented with musical technologies from harpsichords to electronic tone generators, and programmed a good deal of educational and research software. Thus, when Mike Roco approached the directorate in 1999, seeking someone to represent the social sciences on the nanotechnology initiative he was organizing, I was excited to volunteer.